diff options
| author | kib <kib@FreeBSD.org> | 2009-10-27 10:55:34 +0000 |
|---|---|---|
| committer | kib <kib@FreeBSD.org> | 2009-10-27 10:55:34 +0000 |
| commit | 08e50139380f182b37e3e8f5bc7c1319119a4abd (patch) | |
| tree | 707b4bb2816586b23064a94f87f2fbfdd1dc7380 /sys/kern/syscalls.master | |
| parent | ce081b037e7a762f0dd090a207cafc5121f39f51 (diff) | |
| download | FreeBSD-src-08e50139380f182b37e3e8f5bc7c1319119a4abd.zip FreeBSD-src-08e50139380f182b37e3e8f5bc7c1319119a4abd.tar.gz | |
Current pselect(3) is implemented in usermode and thus vulnerable to
well-known race condition, which elimination was the reason for the
function appearance in first place. If sigmask supplied as argument to
pselect() enables a signal, the signal might be delivered before thread
called select(2), causing lost wakeup. Reimplement pselect() in kernel,
making change of sigmask and sleep atomic.
Since signal shall be delivered to the usermode, but sigmask restored,
set TDP_OLDMASK and save old mask in td_oldsigmask. The TDP_OLDMASK
should be cleared by ast() in case signal was not gelivered during
syscall execution.
Reviewed by: davidxu
Tested by: pho
MFC after: 1 month
Diffstat (limited to 'sys/kern/syscalls.master')
| -rw-r--r-- | sys/kern/syscalls.master | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/sys/kern/syscalls.master b/sys/kern/syscalls.master index f96ed79..ac64a75 100644 --- a/sys/kern/syscalls.master +++ b/sys/kern/syscalls.master @@ -919,5 +919,9 @@ 519 AUE_PDKILL UNIMPL pdkill 520 AUE_PDGETPID UNIMPL pdgetpid 521 AUE_PDWAIT UNIMPL pdwait +522 AUE_SELECT STD { int pselect(int nd, fd_set *in, \ + fd_set *ou, fd_set *ex, \ + const struct timespec *ts, \ + const sigset_t *sm); } ; Please copy any additions and changes to the following compatability tables: ; sys/compat/freebsd32/syscalls.master |
